Problem: Simplify the following expression: $n = \dfrac{z - 3}{6} \div \dfrac{7z}{5}$
Dividing by an expression is the same as multiplying by its inverse. $n = \dfrac{z - 3}{6} \times \dfrac{5}{7z}$ When multiplying fractions, we multiply the numerators and the denominators. $n = \dfrac{ (z - 3) \times 5 } { 6 \times 7z}$ $n = \dfrac{5z - 15}{42z}$